A polymer electrolyte membrane fuel cell provided in a fuel cell vehicle necessarily requires moisture in order to be operated. Since the moisture serves as a transfer medium of hydrogen ions in a fuel cell, humidity of air supplied to a fuel cell stack is associated directly with performance of the fuel cell.
Therefore, the fuel cell vehicle has been provided with an air processing system according to the related art, as illustrated in FIG. 1. The air supplied to the fuel cell stack 1 is taken in through a blower 2 provided in an intake pipe, is injected into a humidifier 3, is humidified through the humidifier 3, and is then introduced into the fuel cell stack 1, as illustrated in FIG. 1. The air supplied to the fuel cell stack 1 again passes through the humidifier 3 and is then discharged to the outside through an exhaust pipe.
Meanwhile, in order to control amounts of air introduced into the fuel cell stack 1 and air discharged from the fuel cell stack 1, the intake pipe and the exhaust pipe are provided with air cut valves 4 and 5. After a start of the fuel cell vehicle is stopped, the air cut valves 4 and 5 provided in the intake pipe and the exhaust pipe are closed, and oxygen in the air introduced into the fuel cell stack are consumed to prevent corrosion of cathode carbon provided in the fuel cell.
However, according to the related art, the air cut valves 4 and 5 are positioned at a distance distant from the fuel cell stack, such that a large amount of oxygen is consumed after the start of the fuel cell vehicle is stopped. Therefore, it is difficult to completely prevent the corrosion of the cathode carbon.